#include <stdio.h>
int main()
{
    int day;
    printf("请输入天数:");
    scanf("%d", &day);
    int peach = 1;
    int x;
    for (; day > 1; day--)
    {
        peach = 2 * peach + 2;

        if (day ==2)
        {
            printf("第一天吃了%d个桃子", peach);
        }
    }
}